1. Field of the Invention
The invention relates to an image processing method, and more particularly, to an image processing device and related method for reducing temporal noise of a target frame and enhancing the motion of the target frame.
2. Description of the Prior Art
In general, in order to enable an image signal to have a better displaying effect, the image signal is often processed, for example, a temporal noise reduction operation or a motion enhancement operation may be performed on the image signal. Please refer to FIG. 1, which is a block diagram of a conventional temporal noise filtering device 100. As shown in FIG. 1, the temporal noise filtering device 100 comprises a temporal noise reducing circuit 110 and a storage device 120. The temporal noise reducing circuit 110 receives luminance Y_IN[N] of an Nth frame in an image signal, and reads a filtered signal Y_NR[N−1] from the storage device 120, where the filtered signal is generated by performing the temporal noise reduction operation on the (N−1)th frame. The temporal noise reducing circuit 110 performs the temporal noise reduction operation on the current frame (Nth frame) according to the motion value between the luminance information Y_IN[N] of the current frame and the filtered signal Y_NR[N−1] of the previous frame ((N−1)th frame). The generated result (the filtered signal Y_NR[N] generated by performing the temporal noise reduction operation on the Nth frame) is then output to a next stage (not shown) and the generated result is stored in the storage device 120. From the above illustration, it can be seen that the storage device 120 plays the role of temporary storage and further provides a previous filtered signal to the temporal noise reducing circuit 110.
Please refer to FIG. 2, which is a block diagram of a conventional motion enhancer 200. As shown in FIG. 2, the motion enhancer 200 comprises a motion enhancing circuit 210 and a storage device 220. The motion enhancing circuit 210 receives the luminance information Y_IN[N] of the Nth frame in an image signal and simultaneously stores the luminance information Y_IN[N] into the storage device 220. Moreover, the motion enhancing circuit 210 reads the luminance information Y_IN[N−1] of the previous (N−1)th frame and adjusts the luminance motion of the Nth frame according to the luminance information Y_IN[N] and the luminance information Y_IN[N−1] to enhance the motion of the Nth frame. Similarly, in the motion enhancer 200, the storage device 220 has the function of temporary storage and further provides the information of a previous frame to the motion enhancing circuit 210.
Under most situations, the image signal should be processed through the above-mentioned temporal noise reduction operation and the motion enhancement operation. If, however, the above-mentioned circuits (the motion enhancer 200 and the temporal noise filtering device 100) operate separately, the cost will be high and more hardware will be needed.